Lubrication cartridge for a pneumatically powered surgical instrument

ABSTRACT

An inline oiler cartridge assembly for a pneumatically powered instrument includes a housing, a first conduit and a second conduit. The housing includes a lower portion removably attached to an upper portion. The lower portion defines an inner cylindrical cavity and an outer cylindrical cavity. A source of oil is disposed in the inner cylindrical cavity. A dry fiber cellulose material is disposed in the outer cylindrical cavity. The first conduit has a first end for attachment to a source of pressurized air and a second end for attachment to a pneumatically powered instrument. The first conduit passes through a portion of the upper portion of the housing and defines a channel for transmission of the source of pressurized air. The channel is in fluid communication with the inner cylindrical cavity such that the source of pressurized air draws oil into an air stream for delivery to the pneumatically powered instrument. The second conduit is concentrically arranged with respect to the first conduit and cooperates with the upper portion of the housing to define a path for returning exhaust gases from the pneumatically powered instrument to the outer cylindrical cavity of the lower portion of the housing.

The present application is a divisional of U.S. Ser. No. 10/180,470filed Jun. 26 2002 which claims the benefit of U.S. Ser. No. 60/301,491filed Jun. 28, 2001, U.S. Ser. No. 60/352,609 filed Jan. 28, 2002; U.S.Ser. No. 60/387,626 filed Jun. 11, 2002 all of which are herebyincorporated by reference. The following applications are also relatedand hereby incorporated by reference: U.S. Ser. Nos. 10/102,762 and10/135,608.

FIELD OF THE INVENTION

The presentinvention generally relates to surgical instruments. Moreparticulary, the present invention relates to powered surgicalinstruments for use in the dissection of bone and other tissue and alubrication system for use therewith.

BACKGROUND

Doctors and other medical professionals often use powered surgicalinstruments for dissecting bone and tissue.

Often, it is important to lubricate the instruments for proper use. Forexample, a typical pneumatically powered surgical instrument includes apneumatic motor connected to a fluid supply source. An oil system istypically place inline between the fluid supply source and the pneumaticmotor to provide lubrication to the instrument.

The oil system often must be manually calibrated and/or activatedaccording to predetermine guidelines. For example, the oil system istypically set at a specified drip rate for providing oil into the fluidpath. Maintaining the proper drip rate is important to providing theproper amount of lubrication to the instrument. Numerous drawbacksinherently exist in such a system.

SUMMARY

The present invention provides an improved lubrication system for asurgical instrument. In one embodiment, an inline oiler cartridgeassembly is provided for a pneumatically powered surgical instrument.The inline oiler cartridge includes a housing, a first conduit and asecond conduit. The housing includes a lower portion removably attachedto an upper portion. The lower portion defines an inner cylindricalcavity and an outer cylindrical cavity. A source of oil is disposed inthe inner cylindrical cavity. An absorbent member is disposed in theouter cylindrical cavity. The first conduit has a first end forattachment to a source of pressurized air and a second end forattachment to a pneumatically powered instrument. The first conduitpasses through a portion of the upper portion of the housing and definesa channel for transmission of the source of pressurized air. The channelis in fluid communication with the inner cylindrical cavity such thatthe source of pressurized air draws oil into an air stream for deliveryto the pneumatically powered instrument. The second conduit isconcentrically arranged with respect to the first conduit and cooperateswith the upper portion of the housing to define a path for returningexhaust gases from the pneumatically powered instrument to the outercylindrical cavity of the lower portion of the housing.

In another embodiment, an inline lubricant cartridge assembly for usewith a pneumatically powered surgical instrument is provided. The inlinelubricant cartridge assembly includes a housing with first and secondportions, the first portion defining a first cavity including alubricant-soaked absorbent member. A first conduit having a first endfor attachment to a source of pressurized fluid and a second end forattachment to a pneumatically powered surgical instrument is alsoprovided. The first conduit passes through the second portion of thehousing and defines a channel for transmission of a pressurized fluidstream. The channel is in fluid communication with the first cavity suchthat the lubricant is drawn into the fluid stream for delivery to thepneumatically powered instrument.

In some embodiments, the inline lubricant cartridge assembly alsoincludes a second conduit concentrically arranged with respect to thefirst conduit. The second conduit cooperates with the upper portion ofthe housing to define a path for returning exhaust gases from thepneumatically powered instrument.

In some embodiments, the first portion also defines a second cavityincluding a relatively dry absorbent member. The second conduit is influid communication with the second cavity for passing the exhaust gasesthrough the relatively dry absorbent member.

In another embodiment, a lubricant system for use with a pneumaticsurgical instrument is provided. The system includes a first enclosurepositioned inline of a pressurized fluid path, the first enclosuresequentially defining a large-diameter chamber and a small-diameterchamber registering with the pressurized fluid path. Also, a secondenclosure including a lubricant is provided. A first fluid path isprovided, having a first fluid inlet registering with the large-diameterchamber and a first fluid outlet registering with the second enclosure.A second fluid path is also provided, having a second fluid inletregistering with the second enclosure and a second fluid outletregistering with the small-diameter chamber. A pressurized fluid mayflow through the first enclosure such that at least a portion of thefluid flows from the large-diameter chamber, through the first fluidpath, through the second enclosure, through the second fluid path, andinto the small-diameter chamber.

In another embodiment, an inline oiler for use with a pneumatic surgicalinstrument is provided. The inline oiler includes a first housing havinga first hose fitting for connecting to a source of compressed air and asecond hose fitting for connecting to the pneumatic surgical instrument.The inline oiler also includes a second housing including an oil-soakedabsorbent member. The inline oiler further includes a chamber defined bythe first housing and including a first inlet for receiving pressurizedair from the source, a first outlet for providing a portion of thepressurized air to the second housing, a second inlet for receiving theportion of the pressurized air and a predetermined amount of oil fromthe second housing, and a second outlet for providing the pressurizedair, including the portion from the second housing and the predeterminedamount of oil, to the surgical instrument.

It should be understood that the present summary and the followingdetailed description, while indicating the preferred embodiment of theinvention, are intended for purposes of illustration only and are notintended to limit the scope of the invention beyond that described inthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1A is an environmental view illustrating an inline oiler cartridgeassembly for a pneumatically powered instrument according to theteachings of a preferred embodiment of the present invention shownoperatively coupled to a pneumatically powered instrument.

FIG. 1B is a cross-sectional view taken through the arrangement of FIG.1A, the pneumatic instrument shown in simplified form.

FIG. 2 is a perspective view of the inline oiler cartridge assembly fora pneumatically powered instrument according to the teachings of apreferred embodiment of the present invention.

FIG. 3 is an exploded view of the inline oiler cartridge assembly for apneumatically powered instrument according to the teachings of thepreferred embodiment of the present invention.

FIG. 4A is a side view of a lower hosing portion of the inline oilercartridge assembly for a pneumatically powered instrument according tothe preferred embodiment of the present invention.

FIG. 4B is a perspective view of the lower housing portion of the inlineoiler cartridge assembly for a pneumatically powered instrumentaccording to the preferred embodiment of the present invention.

FIG. 4C is a top view of the lower housing portion of the inline oilercartridge assembly for a pneumatically powered instrument according tothe preferred embodiment of the present invention.

FIG. 4D is a bottom view of the lower housing portion of the inlineoiler cartridge assembly for a pneumatically powered instrumentaccording to the preferred embodiment of the present invention.

FIG. 4E is a cross-sectional view taken along the line 4E-4E of FIG. 4D.

FIG. 4F is a cross-sectional view taken along the line 4F-4F of 4D.

FIG. 5A is a perspective view of an upper housing portion of the inlineoiler cartridge assembly for a pneumatically powered instrumentaccording to the preferred embodiment of the present invention.

FIG. 5B is a side view of the upper housing portion of the inline oilercartridge assembly for a pneumatically powered instrument according tothe preferred embodiment of the present invention.

FIG. 5C is a bottom view of the upper housing portion of the inlineoiler cartridge assembly for a pneumatically powered instrumentaccording to the preferred embodiment of the present invention.

FIG. 5D is a cross-sectional view taken along the line 5D-5D of FIG. 5C.

FIG. 6A is a bottom side view of the first conduit of the inline oilercartridge assembly for a pneumatically powered instrument according tothe preferred embodiment of the present invention.

FIG. 6B is a cross-sectional view taken along the line 6B-6B of FIG. 6A.

FIG. 7A is a cross-sectional view of another embodiment of the presentinvention.

FIG. 7B is a cross-sectional view of the embodiment shown in FIG. 7Arotated 90°.

DETAILED DESCRIPTION

The following description of the preferred apparatus and method of thepresent invention is merely exemplary in nature and is in no wayintended to limit the invention, its application, or uses. Also, it willbecome apparent to those skilled in the art that the subject inventionis not limited to any particular surgical application but has utilityfor various applications in which it is desired to dissect bone or othertissue, including:

-   -   1. Arthroscopy—Orthopaedic    -   2. Endoscopic—Gastroenterology, Urology, Soft Tissue    -   3. Neurosurgery—Cranial, Spine, and Otology    -   4. Small Bone—Orthopaedic, Oral-Maxiofacial, Ortho-Spine, and        Otology    -   5. Cardio Thoracic—Small Bone Sub-Segment    -   6. Large Bone—Total Joint and Trauma    -   7. Dental

With initial reference to FIGS. 1A and 1B, an inline oiler cartridgeassembly for a pneumatically powered surgical instrument according tothe teachings of a preferred embodiment of the present invention isillustrated and generally identified at reference numeral 10. In oneparticular application, the inline oiler cartridge assembly 10 of thepresent invention is used with a pneumatically powered surgicalinstrument 11. A suitable surgical instrument is shown in commonlyassigned U.S. Pat. No. 5,505,737 which is hereby incorporated byreference as if fully set forth herein. However, it will become apparentbelow that the teachings of the present invention have applicability forvarious other powered instruments.

With continued reference to FIGS. 1A and 1B and additional reference toFIGS. 2, 3, 4A-4F, 5A-5D and 6A-6B, the inline oiler cartridge assembly10 of the present invention will be further described. As perhaps mostclearly shown in the exploded view of FIG. 3, the inline oiler cartridgeassembly 10 is shown to generally include a body or housing 12 having anupper portion 14 and a lower portion 16. The inline oiler cartridgeassembly 10 is further shown to generally include a first conduit 18 fordelivering a source of pressurized air to the pneumatically poweredinstrument 11 and a second conduit 20 for returning exhaust gases fromthe pneumatically powered instrument 11 to the housing 12 of theassembly 10. Although the first and second conduits 18, 20 are coaxialin the present description, it is understood that in other embodiments,these conduits may be separate (not coaxial), or one of the conduits maynot be used at all.

With particular reference to FIGS. 4A-4F, the lower portion 16 of thehousing 12 is illustrated to have a generally cylindrical shape. In oneapplication, the lower portion 16 of the housing 12 is injection moldedof plastic. Alternatively other suitable materials may be incorporated.

The lower portion 16 of the housing 12 includes an outer cylindricalwall 22, a concentrically arranged inner cylindrical wall 24, and abottom wall 26. A first generally cylindrical cavity 28 or chamber isdefined between the inner and outer cylindrical walls 22 and 24. Asecond generally cylindrical cavity 30 is defined by the innercylindrical wall 24.

As shown in FIG. 4 f, an oil saturated cellulose fiber material 31 isdisposed in the second cavity 30. Also, a dry cellulose fiber material33 is disposed within the first generally cylindrical cavity orlubricant chamber 28. It is understood that cellulose fiber materials31, 33 are merely examples of absorbent materials, and other examplesinclude foam, wool felt, porous plastics, porous metals and/or othertype materials. In a manner to be further addressed below, oil is drawnfrom the second cavity 30 for introduction into an air stream. Exhaustgases including spent oil are returned to the first cavity 28. The drycellulose fiber material 33 filters the oil from the exhaust gases. Thefiltered exhaust gases are permitted to pass through a plurality ofexhaust apertures 32 provided in the bottom wall 26 of the lower portion16.

With particularly reference to FIGS. 5A-5D, the upper portion 14 of thehousing 12 will be further described. Similar to the lower portion 16,the upper portion 14 is preferably unitarily constructed of plasticthrough an injection molding procedure. Again, alternate materials andmanners of construction can alternatively be employed.

The upper portion 14 of the housing 12 includes a generally cylindricalsegment 36 which is internally threaded. The internal threads 38 engageexternal threads 39 (FIG. 4A) provided on an upper area of the outercylindrical wall 22 of the lower portion 16 such that the upper andlower portions 14 and 16 can be removably secured. An upper segment 40of the upper portion 14 defines a channel 42. A cylindrical portion 44downwardly extends from the upper segment 40 and into the cavity 30(FIG. 4E).

The portion 44 includes one or more apertures 46A-C for providing fluidcommunication between the channel 42 and the cavity 30 and securing theconduit 18. It is understood that there may be several differentconfigurations and sizes of apertures to achieve different results,depending upon the lubrication requirements of the surgical instrument11. In the present embodiment, the smallest aperture 46A allows inwardair pressure to feed into the lubricant chamber 28 thereby pressurizingthe lubricant chamber 28. The middle aperture or central aperture 46Bprojects into the lubricant soaked media of the second cavity 30 andallows lubricant to exit into the air flow passing through the conduit18. The middle aperture 46B has a larger diameter in order to effect apressure differential (drop) between the conduit 18 and lubricantchamber 28 thereby creating a Venturi or “sucking” action and drawinglubricant into the air flow passing through the conduit 18 for deliveryto the pneumatic motor. As shown in the exploded view of FIG. 3, anoiler tube 48 extends from the central aperture 46B down into the cavity30. The largest aperture 46C is a hole through which a mechanicalsecuring device (not specifically shown) is positioned for affixing thefirst conduit 18 to the lubricant chamber 28, as discussed in greaterdetail below.

As particularly shown in FIG. 3, suitable O-rings or gaskets may beemployed. Explained further, a first O-ring 50 provides a seal betweenthe upper portion 14 and the lower portion 16 of the housing 12. Asecond O-ring 52 provides a seal between the cylindrical portion 44 andthe chamber 30.

With particularly reference to FIGS. 6A and 6B, the first conduit 18 ofthe inline oiler cartridge assembly 10 is further illustrated. The firstconduit 18 is a hollow tubular member injection molded of plastic orconstructed of other suitable materials. The first conduit 18 defines acentral channel 54. A first end 56 of the first conduit 18 is intendedto be coupled to an air source (now shown). The first end 56 also ispositioned inside of the channel 42 (FIG. 5D). A second end 58 isreduced in diameter and is adapted to be coupled to the pneumaticallypowered instrument 11 through a hose 59 (FIGS. 1A, 1B). The firstconduit 18 includes radially extending apertures 60A-C that align withthe apertures 46A-C, respectively, of the upper portion 14 of thehousing 12. The mechanical securing device (not shown), such as a setscrew, engages with the apertures 46C and 60C to secure the firstconduit inside the upper segment 40.

As particular shown in FIGS. 2 and 3, the second conduit 20 is a hollowtubular member. The second conduit 20 is received within the cylindricalsegment 40 of the upper portion 14 of the housing 12 and cooperates withthe upper portion 14 to define a fluid path for returning exhaust gasesfrom the pneumatically powered instrument to the outer cylindricalcavity 28 of the lower portion 16. The second conduit 20 concentricallysurrounds the second end 58 of the first conduit 18.

In operation, pressurized air is introduced into the first end 56 of thefirst conduit 18. In one particular application, the air is introducedat a pressure of approximately 120 psi. Further, an on/off controlmechanism, such as a foot pedal, may be disposed between a compressedair source and the instrument 11, such as at the first end 56 of thefirst conduit 18. The pressurized air passes through the channel 54defined by the first conduit 18 and through a Venturi effect draws oilfrom the wet fiber cellulose material 31 in the chamber 30 into the airstream. This oil is atomized and delivered with the air stream into themotor of the pneumatically powered instrument for lubrication. On oneapplication, the atomized oil lubricates the motor within approximately45-50 seconds of startup. This compares with conventional arrangementswhich take approximately 150 to 300 seconds.

Exhaust gases carrying spent oil from the motor of the pneumaticallypowered instrument are returned through the second conduit 20. Theseexhaust gases are introduced into the outer cylindrical chamber 28containing the dry fiber cellulose material through a pathway 62 (shownin FIG. 5D) defined in the upper portion 14 of the housing 12. The dryfiber cellulose material within the cavity 28 filters the spent oil fromthe exhaust gases and allows the exhaust gases to pass through theplurality of apertures 32 in the bottom wall 26.

According to a preferred method of the present invention, the inlineoiler cartridge assembly 10 described above is pre-filled with oil. Theamount of oil is sufficient to ensure lubrication of the motor of thepneumatically powered instrument throughout a surgical procedure.Explaining further, the risk of running out of oil during a surgicalprocedure is effectively eliminated. After the surgically procedure iscompleted, the inline oiler cartridge assembly 10 may be disconnectedfrom the surgical instrument and discarded.

Another embodiment of the present invention is illustrated in FIGS. 7Aand 7B. Lubrication assembly 110 includes many of the same components ofthe previously described embodiments and is intended for operation inthe same environment set forth above. Lubrication assembly 110 includesa body 120 having apertures for receiving inlet air tube 112 and outletair tube 114. Preferably, body 120 is formed from aluminum. It will beunderstood that inlet air tube 112 is connected to a source ofpressurized fluid. Further, as shown in FIG. 1B, a coaxial hose may beconnected to the lubrication housing 110 with a high pressure hosefitted over flanges 116 and the lower pressure exhaust hose receivedwith aperture 118. Body 120 further defines a cylindrical shell 124having an opening at one end to receive a lubrication fluid reservoirand exhaust filter unit as previously described above. Shell 124includes a pair of locking slots 126 adapted to receive projections onthe exterior of the lubrication and filter unit to retain it within thebody 120. Preferably, internal grooves 127 extend from the apertureopening to the grooves 126 such that the projections may be advancedinto the interior of the body 120. It will be appreciated that thehelical path of grooves 126 will tend to advance the lubrication andfilter unit into the body 120. Grooves 126 includes substantially flatportions at their termination such that the lubrication and filter bodywill be locked into position in the body 120 and permitting the seals tosealingly engage the lubrication and filter unit.

Lubrication assembly 110 further includes fluid passageways adapted tocreate fluid flow through the lubrication material (not shown).Specifically, inlet channel 130 having a first diameter is in fluidcommunication with the pressurized fluid from inlet tube 112. A reduceddiameter portion 132 provides a conduit between inlet channel 130 andoutlet channel 136 within outlet tube 114. Within the wall defininginlet channel 130, an aperture communicates with inlet fluid path 142.Similarly, within the wall defining reduced diameter portion, anaperture communicates with outlet fluid path 148. A further component ofthe fluid pathway is extension 140 joined to the body 120 substantiallycentered within cylindrical shell 124. The extension 140 defines aninlet fluid path 144 in communication with inlet fluid path 142 and anoutlet fluid path 146 in communication with outlet fluid path 148. Itwill be understood that the extension 140 generates a longer fluid paththrough the lubrication material to enhance the uniform nature ofatomizing lubricant in the return air stream.

While it is contemplated that the combination of aperture sizes, fluidpassage diameters and lengths may be sized to approximate the desiredairflow through the lubricating material, the present embodimentincorporates a flow control mechanism such that air flow may becontrolled through the lubricating assembly. Specifically, a needlevalve body 150 is received in aperture 162 in the body 120. The needlevalve body 150 includes a needle valve portion 152 extending intoconical valve seat 160 to restrict fluid flow. The needle valve body 150also includes an instrument engaging recess 156 to move it withinaperture 162 via the threaded connection 154.

The embodiment illustrated in FIGS. 7A and 7B operates in a mannersimilar to that of the embodiment previously described. By way ofexample, pressurized fluid entering inlet channel 130 encounters reduceddiameter portion 132, thus restricting flow. As shown by the arrows inFIG. 7A, pressurized fluid may enter inlet fluid path 142 and travelthrough inlet fluid path 144 to exit extension 140 into thelubricant-soaked absorbent material (not shown). As previouslydescribed, the absorbent material may be impregnated with oil or someother lubricant. The pressurized fluid tends to seek a path to escapefrom the lubricant material. As a result of the venturi effect adjacentthe aperture in reduced diameter portion 132, outlet fluid path 146experiences a lower pressure and the higher pressure fluid may flow intothe outlet through outlet path 148 and ultimately into reduced diameterportion 132. As the fluid passes through the lubricant material it picksup small particles or drops of lubricant and carries these elements inthe fluid stream. The lubricating material may then be carried by thefluid to the motor where it performs its lubricating function. It willbe understood that the needle valve 152 may be adjusted to control fluidflow through the lubricating material and thereby control lubricant tothe motor. In a preferred embodiment, the needle valve is set in themanufacturing process to provide lubrication within the requiredspecifications prior to packaging and shipping to the end user. It isanticipated that further adjustments will not be necessary for the enduser. However, it is contemplated that if changes are made to thelubricating material or the pressure of the inlet fluid, modificationsof the needle valve setting may be performed.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

1. A lubricant system for use with a surgical instrument, comprising: afirst enclosure positioned inline with a pressurized fluid path, thefirst enclosure sequentially defining a relatively large-diameterchamber and a relatively small-diameter chamber for defining at least aportion of the pressurized fluid path; a second enclosure including alubricant; an elongated member; a first fluid path extending along theelongated member and having a first fluid inlet registering with thelarge-diameter chamber and a first fluid outlet registering with thesecond enclosure; and a second fluid path extending along the elongatedmember and having a second fluid inlet registering with the secondenclosure and a second fluid outlet registering with the small-diameterchamber; the first outlet and the second inlet being positioned near acentral portion of the second enclosure; whereby a pressurized fluid mayflow through the first enclosure such that at least a portion of thepressurized fluid flows from the large-diameter chamber, through thefirst fluid path, through the second enclosure, through the second fluidpath, and into the small-diameter chamber.
 2. A lubricant system for usewith a surgical instrument, the system comprising: a first enclosurepositioned inline with a pressurized fluid path, the first enclosuresequentially defining a relatively large-diameter chamber and arelatively small-diameter chamber for defining at least a portion of thepressurized fluid path; a second enclosure including a lubricant; afirst fluid path having a first fluid inlet registering with thelarge-diameter chamber and a first fluid outlet registering with thesecond enclosure; a second fluid path having a second fluid inletregistering with the second enclosure and a second fluid outletregistering with the small-diameter chamber; whereby a pressurized fluidmay flow through the first enclosure such that at least a portion of thepressurized fluid floes from the large-diameter chamber, through thefirst fluid path, through the second enclosure, through the second fluidpath, and into the small-diameter chamber; and a valve positioned in oneof the fluid paths for controlling an amount of fluid that flowstherethrough.